By Mark Johnson of the Journal Sentinel
Scientists at the University of Wisconsin-Madison have grown human embryonic stem cells into neurons that appear capable of adapting themselves to the brain's machinery by sending and receiving messages from other cells, raising hopes that medicine may one day use this tool to treat patients with such disorders as Parkinson's and amyotrophic lateral sclerosis, commonly known as Lou Gehrig's disease.
Researchers inserted the human cells into the brains of mice where they successfully integrated themselves into the wiring. Then the UW team applied a new technology, using light to stimulate the human cells and watching as they in turn activated mouse brain cells.
In a lab dish, the brain cells or neurons began firing simultaneously "like a power surge lighting up a building," said Jason Weick, an assistant scientist at UW who worked on the study published online Monday in the journal Proceedings of the National Academy of Sciences.
Weick said the use of light stimulation, called optogenetics, raises the possibility of modifying transplanted brain cells, in effect turning them up or down like the dimmer control on a light.
"You can imagine that if the transplanted cells don't behave as they should, you could use this system to modulate them using light," said Su-Chun Zhang, a UW professor of neuroscience and one of the authors of the new study.
For years, scientists have talked of the possibility of growing neurons in a dish to replace damaged cells in the brain, but there always have been questions about whether the transplanted cells could become fully functional.
But the new work at UW suggests the idea may be poised to make the transition from theory to reality.
